1. Field of the Invention
This invention relates generally to a magnetic head cleaning disk. More specifically, it concerns a thin flexible platter having a coating that is mildly abrasive for cleaning magnetic read/write heads in a disk system. The coating is highly magnetic for recording thereon, and a program can be written that instructs the disk system to cycle the heads across the coating surface for thorough cleaning.
2. Description of the Prior Art
In flexible disk systems, magnetic heads that contact the magnetic recording coating of diskettes tend to become covered with magnetic particles, binder and lubricant. Such deposits interfere with recording and playback operations, and must be periodically removed. Since the magnetic head is generally positioned within an interior portion of the disk system, it cannot be readily cleaned with a cloth soaked in a solvent, as in the case of open reel tape recorders and cassette recorders. One way to clean the magnetic heads is with a cleaning disk that is inserted into the disk system and rotated. Such disks have used a non-woven polyester fiber that smears oxide debris in the head area. Other disks have used an abrasive that tends to scratch and scrape the heads.
A head cleaning tape for video tape recorders is disclosed in U.S. Pat. No. 3,978,520 to Nowicki, et al. This tape has a coating including magnetic chromium dioxide that is highly abrasive. The coating is magnetically recorded upon to bear a video test pattern, and cleaning operation is stopped when the test pattern is clearly visible. This patent also mentions a Sony HC Tape that has a magnetic iron oxide coating.
U.S. Pat. No. 4,180,840 to Allen shows a cleaning disk with an abrasive surface on one side, positioned within a reversible container having special apertures which enable system software to determine the abrasive surface orientation. This assembly is used in a disk system having two transducer/pad pairs, oppositely-oriented so that both sides of the disk can be read. A system is disclosed for sweeping the transducers across the disk surface to equalize wear of the abrasive side.
A tape having an information bearing section and a cleaning section connected in series is disclosed in U.S. Pat. No. 3,069,815 to Valentine. The cleaning section has an absorbent cleaning material portion and an abrasive material portion. The abrasive material is ferric oxide (Fe.sub.2 O.sub.3) in a binder described in U.S. Pat. No. 2,989,415 to Horton et al.
A floppy disk with a fibrous material layer for cleaning magnetic heads is disclosed in U.S. Pat. No. 4,065,798 to Sugisaki et al., and a similar disk is disclosed in U.S. Pat. No. 4,106,067 to Masuyama et al.. A floppy disk having a thin oxide coating for protecting and lubricating a recording disk is taught by U.S. Pat. No. 3,353,166 to Brock.